There was a very interesting article in the Economist about this. The gist of it is that 24% is indeed steep, but bear in mind that:
a) These are very small sums of money, so the proportional overhead is much higher
b) Microfinance loans represent about 30% of loans, the rest coming from local loansharks, who typically charge around 2-300% apr (and have more violent debt collection procedures). Any cap on rates will lower that percentage, and so make things worse.
a) These are very small sums of money, so the proportional overhead is much higher b) Microfinance loans represent about 30% of loans, the rest coming from local loansharks, who typically charge around 2-300% apr (and have more violent debt collection procedures). Any cap on rates will lower that percentage, and so make things worse.